1. Field
Aspects of the present invention relate to lithium air batteries.
2. Description of the Related Art
A lithium air battery generally includes a negative electrode capable of intercalating and deintercalating lithium ions, a positive electrode that oxidizes and reduces oxygen present in the air, and an electrolyte interposed between the negative electrode and the positive electrode.
In the lithium air battery, lithium is used as a negative electrode and air, as a positive active material, does not need to be stored therein. Thus, a lithium air battery with a high capacity may be obtained. Lithium air batteries have a theoretical energy density of 3,500 Wh/kg or greater, which is approximately 10 times greater than that of lithium ion batteries.
However, existing lithium air batteries have significantly lower energy efficiency than that of lithium ion batteries. This is due to the polarization caused by the high overvoltage during the charging and the discharging.
To lower the charge-discharge overvoltage, various kinds of catalysts have been used, but the reducing effects have been insufficient. Therefore, there is still a need to develop a method of improving charge-discharge energy efficiency by reducing the charge-discharge overvoltage.